Study Finds Fish Oil May Reduce Risk Of Breast Cancer

A recent report in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, adds to the evidence that fish oil supplements may play a role in preventing chronic disease.

Researchers at the Fred Hutchinson Cancer Research Center in Seattle, Wash., led by Emily White, Ph.D., a member of the public health sciences division, asked 35,016 post-menopausal women who did not have a history of breast cancer to complete a 24-page questionnaire about their use of non-vitamin, non-mineral “specialty” supplements in the Vitamins and Lifestyle (VITAL) cohort study.

After six years of follow-up, 880 cases of breast cancer were identified using the Surveillance, Epidemiology and End Results registry.
Regular use of fish oil supplements, which contain high levels of the omega-3 fatty acids, EPA and DHA, was linked with a 32 percent reduced risk of breast cancer. The reduction in risk appeared to be restricted to invasive ductal breast cancer, the most common type of the disease.

The use of other specialty supplements, many of which are commonly taken by women to treat symptoms of menopause, was not associated with breast cancer risk.

This research is the first to demonstrate a link between the use of fish oil supplements and a reduction in breast cancer. Studies of dietary intake of fish or omega-3 fatty acids have not been consistent.

“It may be that the amount of omega-3 fatty acids in fish oil supplements are higher than most people would typically get from their diet,” White said.

However, White cautioned against gleaning any recommendations from the results of one study.

“Without confirming studies specifically addressing this,” she said, “we should not draw any conclusions about a causal relationship.”

Edward Giovannucci, M.D., Sc.D., professor of nutrition and epidemiology at the Harvard School of Public Health and an editorial board member of Cancer Epidemiology, Biomarkers & Prevention, agreed.

“It is very rare that a single study should be used to make a broad recommendation,” said Giovannucci. “Over a period of time, as the studies confirm each other, we can start to make recommendations.”
Still, fish oil continues to excite many, as evidence emerges about its protective effect on cardiovascular disease and now cancer.

Harvard researchers are currently enrolling patients for the randomized Vitamin D and Omega-3 Trial (also called VITAL), which will assess the impact of fish oil supplements and vitamin D on cancer, heart disease and stroke.

The researchers plan to enroll 20,000 U.S. men aged 60 years and older and women aged 65 years and older who do not have a history of these diseases and have never taken supplements.

Recruitment for this National Institutes of Health funded study began in January, and more information can be found at www.vitalstudy.org.

Agave Joins The Fight Against Osteoporosis

Agave, the plant that gave the world tequila contains a substance that seems ideal for use in a new genre of processed foods — dubbed “functional foods” — with health benefits serving as a source of nutrients, scientists reported at the 239th National Meeting of the American Chemical Society (ACS) in San Francisco on March 23.

Foods spiked with “fructans” from the agave plant may help protect against osteoporosis by boosting the body’s absorption of calcium and could have other health benefits, the scientists said.

“Fructans are considered functional food ingredients because they affect body processes in ways that result in better health and reduction in the risk of many diseases,” said Mercedes López, Ph.D., who delivered the report.

“Experimental studies suggest that fructans may be beneficial in diabetes, obesity, stimulating the immune system of the body, decreasing levels of disease-causing bacteria in the intestine, relieving constipation, and reducing the risk of colon cancer,” said López, serving as a representative for the National Polytechnic Institute, Guanajuato, Mexico.

Fructans are non-digestible carbohydrates. They consist of molecules of fructose — the sugar found in honey, grapes, and ripe fruits — linked together into chains. Rich natural sources include artichokes, Jerusalem artichokes, garlic and onions, and chicory. Fructans do not occur in tequila, however, because they change into alcohol when agave is used to make tequila, López said.

So-called “inulin-type” fructans from chicory find wide use in the United States and other countries in ice cream, breakfast cereals, baked goods, sauces, beverages, and other foods. Small fructans have a sweet taste, while those formed from longer chains of fructose have a neutral taste and give foods a smooth, pleasant texture.

Scientific studies have suggested that fructans stimulate the growth of healthful bacteria in the large intestine in a way that increases the body’s absorption of minerals, including the calcium and magnesium important for bone growth.

In the new study, López and colleagues set out to determine what effects agave fructans actually have on bone growth. They tested the effects of agave fructans on laboratory mice, used as stand-ins for humans in such research. Mice fed agave fructans absorbed more calcium from food, excreted less calcium in their feces, and showed a 50 percent increase in levels of a protein associated with the build-up of new bone tissue.

“These results suggest that the supplementation of the standard diet with agave fructans prevented bone loss and improved bone formation, indicating the important role of agave fructans on the maintenance of healthy bone,” López said. “They can be used in many products for children and infants to help prevent various diseases, and can even be used in ice cream as a sugar substitute.”

López said her findings suggest that agave fructans could be used in all of the same foods as chicory fructans. One advantage: Agave grows abundantly in Mexico and other countries with climates that do not favor growth of chicory.

In addition, the scientists cited hints from past research that agave fructans may have greater health benefits. Agave fructans, for instance, seem to stimulate production of greater amounts incretins than the inulin-type fructans from chicory. Incretins are a group of gastrointestinal hormones that increase in the amount of insulin released by the pancreas. That could be beneficial for individuals with diabetes or high blood sugar levels who are at risk of diabetes, López said. One incretin stimulated by agave fructans is a good satiety enhancer, which would make people feel full on less food.

“We still have a long way to go to determine for which health benefits agave fructans perform better than chicory fructans,” López said. “However, the early results are encouraging, and we working on it.”

For more information on the study, visit: www.acs.org.

Vertebral Fracture May Be Causing Postmenopausal Height Loss

Height loss is common as people age and is associated with back pain. Causes include changes in the curvature of the spine, narrowing of intervertebral discs and vertebral fractures. Two-thirds of adults have back pain at any time, according to the Canadian Medical Association Journal.

Diagnosing these treatable disorders, however, sparks controversy because it is not known if the benefits outweigh the harm of unnecessary radiographs.

Researchers from France conducted a study to compare postmenopausal women and analyze reasons for height loss. The study included 1779 randomly selected general practitioners who were each asked to recruit five female patients over the age of 60. A total of 8610 patients were included in the study.

“We observed a mean loss of height of 4.5 cm since early adulthood in a large population of postmenopausal women in primary care practices,” wrote Dr. Karine Briot, Hôpital Cochin and Université Paris Descartes, Paris, France and co-authors.

“We found that the risk of an existing vertebral fracture was significantly higher among patients with a height loss of at least 4 cm,” Briot continued.

The authors concluded that measurement of height loss could be an accurate method for detecting vertebral fractures. Actual height of women was different from what the patients reported.

General practitioners need to measure patients and not rely on estimates, Briot recommended.

For more information, visit: www.cma.ca/cmaj.

Lasofoxifene Helps Reduce Risk of Bone Fractures, Breast Cancer And Other Postmenopausal Conditions

Low doses of the medication lasofoxifene can reduce the risk of vertebral and non-vertebral fractures, ER-positive breast cancer, coronary heart disease and stroke in postmenopausal women with osteoporosis, according to the findings of a new study in the latest issue of the New England Journal of Medicine.

Lasofoxifene is a non-steroidal selective estrogen receptor modulator (SERM) that has been shown to decrease bone loss and bone weakening, and reduce cholesterol levels, all common problems in postmenopausal women. However, its impact on other health issues for this population was not well understood.

“This is the first SERM that reduces the risk of all of these conditions at once,” says Steven Cummings, M.D., of the San Francisco Coordinating Center at the California Pacific Medical Center (CPMC) Research Institute, and the lead author of the study. “Not only did it reduce vertebral fractures, which was not unexpected, it also reduced the risk of non-vertebral fractures – injuries to the arms, legs, ribs, hips – that are the most common injuries to people with osteoporosis and the main causes of disability.”

The researchers followed 8,556 women, ages 59 to 80, over the course of 5 years. Two thirds of the women were given a daily dose of lasofoxifene (either 0.25mg or 0.5mg) and the other third were given a placebo.

The women were given lateral spine radiographs at 12, 24, 36, and 60 months to measure bone density and identify possible fractures. The women also underwent annual mammograms and clinical breast exams to detect breast cancer.

At the end of the five years patients who took lasofoxifene experienced fewer vertebral fractures than the placebo group – a 58 percent reduction in the patients taking 0.5mg a day and 31 percent in the lower dose group – and non-vertebral fractures (24 percent and 10 percent respectively). Those taking lasofoxifene also experienced increases in bone density compared to the placebo group.

Patients taking lasofoxifene experienced a reduction in their risk of estrogen receptor (ER) positive breast cancer (81 percent and 48 percent respectively), and a reduction in LDL (the so-called bad) cholesterol of around 16 percent.

The researchers say the results were not all positive. Patients taking lasofoxifene were at higher risk of experiencing a venous thromboembolic event or blood clot.

“We know that other SERMs, such as raloxifene, also increase a person’s risk of blood clots, so this finding was not a surprise to us,” says Dr. Cummings. “Even so, we have never found a treatment that has the array of beneficial effects as lasofoxifene with fewer serious side effects. With other treatments, such as Tamoxifen and estrogen, we have seen an increased risk for women of endometrial cancer but in lasofoxifene we did not see that at all.”

While the study results are promising the drug is unlikely to be available to women in the U.S. any time soon. The FDA recently rejected pharmaceutical company Pfizer’s request for approval, meaning that while it is approved and available in Europe, it is not available here in the U.S.

Dr. Cummings and several of the other researchers involved in this study received consulting grants from Pfizer, the manufacturer of lasofoxifene. However, to reduce questions about conflict of interest or bias an independent scientific advisory committee, consisting of investigators not employed by Pfizer, oversaw the study design and analysis, and wrote the paper and approved it for publication, said CPMC.

For more information, visit: www.cpmc.org.

Controversial Studies Trigger Drop Off in Osteoporosis Treatment, Dr. Disputes

Dr. Angelo Malamis said that 90 percent of his patients who have undergone a treatment called balloon kyphoplasty for vertebral fractures report significant reductions in pain and disability.

But the number of kyphoplasty referrals Malamis has received from primary care doctors has dropped sharply since two controversial studies were published last year in the New England Journal of Medicine. In findings that have been disputed by two medical societies, researchers reported that a procedure related to kyphoplasty was not significantly better than a placebo-like procedure in reducing pain and disability.

The North American Spine Society and the Society of Interventional Radiology have pointed to flaws in both studies. And earlier studies, published over 15 years, found major benefits to kyphoplasty and a related procedure called vertebroplasty.

“We’re missing opportunities for patients to receive a safe and effective treatment that can significantly reduce their pain and disability,” said Malamis, an interventional radiologist.

The procedures are used to treat vertebral compression fractures in patients with osteoporosis and other conditions that result in brittle bones. In a vertebroplasty, an acrylic cement is injected into a fractured vertebra. In a kyphoplasty, a balloon-tipped catheter first is inserted into the fracture. The balloon is inflated to restore the height and shape of the vertebra before the cement is injected.

Neva Nelson, 74, of Naperville, Ill., said a kyphoplasty that Malamis performed in October, 2009, has greatly reduced her pain in a vertebra in her lower back that she fractured after falling on ice. Before her kyphoplasty, Nelson had to sit on cushions. Walking, and especially standing, were painful. “I had to do something,” she said. “I could not go on like that.”

Nelson said that since undergoing her kyphoplasty, “I don’t have to worry about my back any more.”

In the controversial studies, patients were randomly assigned to receive a vertebroplasty or a placebo-like “sham” procedure. In the sham procedure, patients received an injection of anesthetic, but no cement.

However, patients in severe pain are reluctant to enroll in a trial where there’s a 50 percent chance of receiving a sham treatment. In one of the studies, researchers had to screen 1,813 patients to enroll just 131 subjects. In the other study, only 78 of 219 eligible patients were enrolled. This low enrollment rate raises the possibility that the patients who did enroll were not representative.

Patients experience the greatest pain during the first three months after a compression fracture. Thereafter, pain gradually subsides. Thus, a vertebroplasty or kyphoplasty provides the greatest benefit when performed within a week or two of the fracture. But the studies enrolled patients up to 12 months after fractures.

In addition to reducing pain and disability, a kyphoplasty can reduce the risk of subsequent fractures by improving the angle and height of the spine. The studies evaluated vertebroplasty alone, and did not include the more innovative and very different kyphoplasty procedure.

Malamis suggests the medical community wait for the results of additional studies now underway before passing final judgment on vertebroplasty or kyphoplasty. In the mean time, he notes that Medicare still covers the procedures.

Malamis is an assistant professor in the Department of Radiology at Loyola University Chicago Stritch School of Medicine.

For more information, visit: www.meddean.luc.edu/.

Improved quality of life for older women on HRT, Study Agreed

Hormone replacement therapy (HRT) can improve the health related quality of life of older women, according to recent research, “Research paper: Health related quality of life after combined hormone replacement therapy: randomized controlled trial.”

HRT guidelines should be reviewed in light of this evidence, said the authors.

Previous research has suggested that HRT can improve general quality of life and reduce the number and severity of symptoms associated with the menopause; but these studies have used general rather than more sensitive condition specific measures.

The WISDOM trial began in 1999 and aimed to evaluate the long term benefits and risks of HRT in postmenopausal women over 10 years. It randomized 5,692 healthy women aged 50–69 from general practices in the UK, Australia and New Zealand to receive either combined HRT (oestrogen and progestogen) or placebo.

All women were monitored for an average of 12 months, and in addition to the main clinical outcomes of cardiovascular disease, fractures and breast cancer, a detailed assessment of the impact of HRT on quality of life was recorded, said researchers.

Quality of life was measured using a modified version of the women’s health questionnaire designed to assess physical and emotional components of health such as depressed mood, memory and concentration, sleep problems and sexual functioning, as well as a symptoms questionnaire.

After one year, the researchers found significant improvements in sexual functioning, sleep problems and vasomotor symptoms (hot flashes and sweats) in the combined HRT group compared to the placebo group.

Significantly fewer women in the HRT group reported:

• hot flashes – 9 percent v.s. 25 percent (placebo),
• night sweats 14 percent v.s. 23 percent,
• aching joints and muscles 57 percent v.s. 63 percent,
• insomnia 35 percent v.s. 41 percent; and
• vaginal dryness 14 percent v.s. 19 percent.

An increase in breast tenderness 16 percent v.s. 7 percent and vaginal discharge 14 percent v.s. 5 percent was recorded by researchers.

Other menopausal symptoms, depression and overall quality of life were not significantly different in the two groups, said researchers.

These results are consistent with the findings of the Women’s Health Initiative and support the conclusion that after one year, women who started taking combined HRT many years after the menopause, experienced reduced hot flashes and night sweats, improved sleep and less bodily pain, said the authors.

These findings may have important benefits for many symptomatic women, the authors claimed , but they caution that the health related quality of life benefits must be weighed against the risk of increased cardiac events, venous thromboembolism and breast cancer.

To access the complete report, please visit: http://press.psprings.co.uk/bmj/august/HRT.pdf.

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Link Between Migraines And Reduced Breast Cancer Risk Confirmed In Follow-up Study

The relationship between migraine headaches in women and a significant reduction in breast cancer risk has been confirmed in a follow-on study to research published last year and conducted by scientists at Fred Hutchinson Cancer Research Center.

The new study found a 26 percent reduced risk of breast cancer among both premenopausal and postmenopausal women with a clinical diagnosis of migraines.

The study appears in the July 2009 issue of Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research. It was led by Christopher I. Li, M.D., Ph.D., a breast-cancer epidemiologist and associate member of the Hutchinson Center’s Public Health Sciences Division. Li led the first-of-its-kind study linking migraines with breast cancer risk reduction that was published in the same journal last November.

This time researchers found that the risk reduction remained statistically similar regardless of a woman’s menopausal status, her age at migraine diagnosis, use of prescription migraine medications or whether she avoided known migraine “triggers” such as alcohol consumption, smoking and taking hormone replacements. These triggers are also well-established breast cancer risk factors.

Some key differences between this study and the initial one that discovered the link include:

• The sample size was more than four times larger this time – more than 4,500 cases and controls versus about 1,000 each in the first study – and was more diverse geographically, drawing women from five metropolitan areas instead of only one. “From an epidemiological perspective, having a larger and more diverse study in its underlying population helps in replicating the finding,” Li said.
• The age range of women studied was wider this time, 34-64 years of age versus 55-74 years old. “We were able to look at whether this association was seen among both pre-menopausal and post menopausal women,” Li said. “In breast cancer this is relevant because there are certain risk factors that are different between older and younger women. In this study we saw the same reduction in breast cancer risk associated with a migraine history regardless of age.”
• Researchers were able to ascertain whether women in the study had lifestyle behaviors that are known migraine triggers – alcohol consumption, smoking and taking hormone replacement therapy. Researchers posited that perhaps women who had migraines drank and smoked less and didn’t take hormone replacements. “But in this study we looked at women who never drank, never smoked and who also didn’t use hormones and found the same association within each of those groups, suggesting that the association between migraine and reduced breast cancer risk may be independent of those other factors and may stand alone as a protective factor,” he said.

What remains unknown is how migraine confers its apparent protection against breast cancer. “We know that migraine is definitely related to hormones and that’s why we started looking at this in the first place,” Li said. “We have different ideas about what may be going on but it’s unclear exactly what the biological mechanisms are.”

In the meantime, research on migraines and breast cancer continues. Li and his colleagues are conducting a follow-up investigation among the women in the first study to determine the types, timing, intensity and severity of their migraines in hopes that the data may elicit additional clues.

And, the research group has submitted a third study for publication that found that the association between migraine and reduced breast cancer risk holds up independent of whether women with migraine took non-steroidal anti-inflammatory drugs such as aspirin and ibuprofen. Earlier studies linked these medications to reduced breast cancer risk as well.

For more inforamtion: www.fhcrc.org.

Menopause: Agent Provides Treatment Option For Women With Hot Flashes

 A pill used for nerve pain offers women relief from hot flashes, Mayo Clinic researchers reported at the 45th Annual Meeting of the American Society of Clinical Oncology (ASCO). 

Researchers said the agent, pregabalin, decreased hot flash severity and frequency about 20 percent more than did a placebo agent. Thus, pregabalin appears to offer about the same benefit as gabapentin, an older, related drug, as well as newer classes of antidepressants. 

“Hot flashes are a major problem in many women, and for those who opt not to take hormonal therapies or antidepressants, pregabalin appears to be another treatment option,” said the study’s lead author, Dr. Charles Loprinzi, a medical oncologist at the Mayo Clinic in Minnesota. 

While pregabalin offers about the same benefit as gabapentin, women who use it only need to take two pills a day, versus three for gabapentin, he said. Side effects can occur with the use of either drug.

However, in this study, they were not severe enough that participants stopped using the active study drug any more often than did patients who were taking placebos, researchers said. 

Gabapentin, an agent that has long been on the market to treat pain caused from injury to nerves, has been shown to decrease hot flashes more than do placebos.

This drug is approved by the Food and Drug Administration (FDA) to treat diabetic peripheral neuropathy and for shingles; anecdotal evidence suggested that menopausal women who used it had a reduction in hot flashes, Loprinzi said.

Multiple placebo-controlled studies have since demonstrated that this drug decreases hot flashes. Gabapentin and a variety of antidepressants are now commonly prescribed for treatment of hot flashes, although these agents are not specifically approved by the FDA for such use.

Pregabalin is a newer version of gabapentin. “We thought it might also relieve hot flashes and thus was worth testing,” Loprinzi said. 

Using funds from the National Cancer Institute, Loprinzi and colleagues set up a 207-participant study conducted by the North Central Cancer Treatment Group (NCCTG).

The study was a Phase III double-blinded, placebo-controlled randomized trial, testing three different treatment arms: a placebo versus daily doses of 150 milligrams (mg) of pregabalin (75 mg twice a day) and 300 milligrams (150 mg twice a day).

Patients getting pregabalin started off with lower doses which were increased weekly to the eventual full dose. Participants, who reported having at least 28 hot flashes a week, kept a “hot flash diary” in which they recorded the number and severity of hot flashes they had each day while taking their study drug — the content of which was unknown to them, researchers said. In the study group, 34 percent were using anti-estrogen therapy — either an aromatase inhibitor, raloxifene, or tamoxifen — to help prevent the recurrence of estrogen-sensitive breast cancer.

The researchers found that for the 163 patients for whom information was available, both doses of pregabalin reduced hot flashes to about the same degree, but that toxicities, such as cognitive dysfunction, were increased at the higher dose.

Other reported side effects included weight gain, sleepiness, dizziness, coordination troubles, concentration troubles, and concerns regarding vision changes. They found that, after six weeks of treatment, women using a placebo agent reported about a 50 percent decrease in their hot flash score (severity), but the change was greater for those who used a 75-milligram twice daily dose of pregabalin (65 percent decrease) and a 150-milligram twice daily dose (71 percent decrease).

The declines in hot flash frequency were 36 percent for placebo users, 58 percent in women who used lower-dose pregabalin, and 61 percent in women given the higher dose. 

“All in all, this study demonstrates that we have another agent to add to the list of medications that offer benefit against hot flashes, even in women using anti-estrogen therapies,”  Loprinzi said. Pfizer, the company that manufactures pregabalin, donated both the drug and placebo tablets for this study. 

For more information, visit: www.mayoclinic.com.

Cedars-Sinai Opens Women’s Clinic At Heart Center, Targeting Heart Disease And Menopause

Women who are at risk for heart disease and who are also experiencing menopause symptoms now have an added resource – a highly specialized clinic in the Division of Cardiology at the Cedars-Sinai Heart Institute.

The Advanced Preventive Women’s Clinic at the Women’s Heart Center recently opened and is offering comprehensive cardiac risk assessments designed specifically for women who are in menopause. The clinic also offers menopausal patients screenings, as well as personalized medicine therapies and counseling, including high-risk hormone counseling.

“This clinic is designed for women who are at higher risk for heart disease and who are seeking to treat their menopause symptoms while simultaneously taking steps to prevent heart problems,” said Dr. Chrisandra Shufelt, assistant director of the Cedars-Sinai Women’s Heart Center. “Menopause is a time to assess your heart health so that the next chapter of your life can be as productive as your youth.”

Each woman who comes to the clinic completes a comprehensive questionnaire that includes her heart risk factors as well as her own menopause symptoms. This personalized medicine approach enables her doctors to tailor a treatment plan that is uniquely hers – one that is based on her medical history, risk factors and symptoms. Risk factors include a family history of heart disease, elevated blood pressure, obesity, and a woman’s own medical history – such as pre-diabetes, complex blood cholesterol disorders or resistant high blood pressure, said Cedars-Sinai.

“Hormone treatment counseling is important for all women experiencing menopause, but it’s especially important for women who are also at risk for heart disease,” said Shufelt. “Before menopause, a woman’s natural estrogen levels often help maintain a healthy balance between HDL (good cholesterol) and LDL (bad cholesterol) levels. However, during menopause, as a woman’s estrogen levels shift, so, too, do her cholesterol levels, with the bad cholesterol levels typically increasing, which can lead to heart disease.”

The Advanced Preventive Women’s Clinic offers hormone therapy counseling as well as non-hormonal options, said Shufelt. The decision as to which provides the better treatment for each individual is determined by the woman’s own symptoms, risk factors and medical history.

Some women – especially those who have had a prior heart attack, bypass surgery or mini-strokes — may not be appropriate for hormone therapy, but no one needs to suffer with menopause symptoms, Shufelt said. In cases where hormone therapy is not advisable, there are other non-hormonal options and lifestyle modification to consider.

“Hormones can be a confusing area,” said Shufelt. “While there are some compound hormones or mixed hormones available on the market, these are not FDA regulated, and we do not offer them,” she said. Instead, the Clinic offers only FDA-approved synthetic or bio-identical hormones, which are a form of hormone that are made from natural substances such as yams. Bio-identical hormones mimic the body’s own form of estrogen.

Beyond hormone counseling, the Clinic also provides lifestyle recommendations. Avoiding alcohol and caffeine can help reduce hot flashes, said Shufelt. Other tips include layering clothing and choosing fabrics that wick away moisture.
Research is also part of the equation. “There is currently a study underway to evaluate the possible benefits of acupuncture for women who experience hot flashes, and there have also been studies on the benefits of yoga and meditation for women with heart disease,” said Shufelt.

“Many women who have already been on hormone therapy for an extended period of time (more than five years), have questions,” said Shufelt. “We work with them to provide the information they need to be a part of their own treatment planning. Women who are on hormone therapy should be re-evaluated each year to assess their risks and benefits and determine the course of action that is best for them.”

For more information, visit: www.csmc.edu.

Study Examines Effects Of Exercise On Quality Of Life In Postmenopausal Women

Exercise appears to improve quality of life in postmenopausal women regardless of whether they lose weight, according to a report in the Archives of Internal Medicine.

Physical inactivity is a risk factor for various chronic conditions including diabetes mellitus, heart disease, stroke and several types of cancers, according to background information in the article. Regular physical activity is often reported to improve mood, reduce stress and increase energy levels, all of which are measurements of quality of life. However, these claims are largely derived from studies composed of participants with serious illnesses and have not been confirmed in healthy populations.

Dr. Corby K. Martin, of the Pennington Biomedical Research Center and Louisiana State University System, Baton Rouge and colleagues studied the effect of 50 percent, 100 percent and 150 percent of current public health physical activity recommendations on quality of life in 430 sedentary postmenopausal women (average age 57.4).

Participants were randomly assigned to a non-exercise control group (n=92) or one of three exercise groups: exercise energy expenditure of 4 kilocalories per kilogram (2.2 pounds) of body weight per week (4-KKW) (n=147), 8-KKW (n=96) or 12-KKW (n=95). A short health survey was used to measure physical and mental aspects of quality of life at the beginning of the study and six months later.

“Adherence to exercise was 95.4 percent, 88.1 percent and 93.7 percent for the 4-, 8- and 12-KKW groups, respectively, and each group spent 73.9, 138.3 and 183.6 minutes per week exercising,” the authors wrote. The average weight loss in the control, 4-KKW, 8-KKW and 12-KKW groups was 0.94 kilograms (2.07 pounds), 1.34 kilograms (2.95 pounds), 1.86 kilograms (4.10 pounds) and 1.34 kilograms (2.95 pounds), respectively.

“A dose-response effect of exercise on quality of life was noted for all aspects of quality of life except bodily pain,” they noted. “In addition, the 4-KKW group had significantly improved general health perception, vitality and mental health compared with the control group. All three exercise groups had significantly improved social functioning compared with the control group.”

“Our results indicate that improved quality of life can be added to the list of exercise benefits and that these improvements are dose dependent and independent of weight loss, at least among people similar to this study’s sample,” the authors concluded. “The exercise doses are easily obtainable and were well tolerated by sedentary women, resulting in confidence that the exercise doses used in this study can be achieved by women in the community.”

This study was supported by grants from the National Institutes of Health. Life Fitness (Schiller Park, Illinois) provided exercise equipment. For more information, please visit: www.jamamedia.org.